Spatial patterns of flow and their modification within and around a giant kelp forest

• DOI: 10.4319/lo.2007.52.5.1838
• Publication Date: 2010-11-16T08:09:19Z
• Authors: Brian Gaylord; Johanna H. Rosman; Daniel C. Reed; Jeffrey R. Koseff; Jonathan Fram; Sally MacIntyre; Katie Arkema; Cameron McDonald; Mark A. Brzezinski; John L. Largier; Stephen G. Monismith; Peter T. Raimondi; Brent Mardian
• Keywords: Kelp forest; Macrocystis pyrifera

We present findings from two sets of measurements that quantified currents around and over the full extent a giant kelp ( Macrocystis pyrifera ) forest located at Mohawk Reef, Santa Barbara, California. Velocities were damped inside this 200‐m X 300‐m forest, but not to reported for larger (kilometer‐scale) beds, suggesting alongshore may play greater role in exchange than has often been assumed. Secondary flow features bear on performance organisms observed, including region along forest’s outer boundary where velocities exceeded incident speeds by up 200%. An offshore current order 1 cm s −1 developed within bed, likely due pressure gradients established across coupled with topography. Wake recirculations might have facilitated leeward retention waterborne subsidies apparent. Calculations suggest beds can interact (and thus potentially filter) substantial portions impinging waters; our study, 40–90% arriving waters entered upstream end, 20–70% reached center forest. Seasonal changes size density modified levels damping filtration. The sum these effects suggests potential influences throughout community.